Traditionally, data centers are powered by relatively inefficient energy sources, relying on traditional fossil fuels that generate significant emissions. According to the NRDC, in 2013 data centers used 91 billion kilowatt hours (kWh) of electrical energy and it’s estimated they will be using 120 billion kWh by 2020, a 53% increase. This growth in energy usage, and subsequent increase in CO2 and other hazardous pollutant emissions, has provided the data center industry the opportunity to look into ways to reduce a data center’s energy footprint while increasing the efficiency of these mammoth energy consumers.
Increasing efficiency often leads to looking toward utilizing often unproven generation resources. Renewable resources, though an efficiency and clean source of power, are just beginning to enter the data center power generation equation and, along with their benefits, offer challenges in reliability due to the intermittency in which they are created. Wind and solar are beginning to be utilized in some sites across the U.S., but biogas was yet to be tested in a real-world scenario. Biogas, a renewable resource created as a byproduct of waste water reclamation facility operations, had yet to be proven in a fully-functioning data center environment but offers enormous benefits.
Fuel cells are also an important piece of the power generation equation. Integrating highly efficient fuel cells that can already achieve significant reduction in emission from the power supply in the grid, biogas can offer a dramatic improvement in emissions over a traditionally sourced energy supply. For example, an average fossil fuel plant emits 1,833 tons of CO2 compared to 940 tons of CO2 from a natural gas fuel cell. This is already a 46% emission reduction. But, a biogas fuel cell results in zero CO2 emissions, resulting in a 100% reduction.
Utilizing biogas and fuel cell technology to power a data center results in zero impact to the grid since the power is consumed directly on-site. It is secure and low-cost since it eliminates the need for backup generators and can incorporate fault tolerant applications. Biogas, created as a byproduct of waste-water treatment and reclamation facilities, is highly available and a strong option for clean, efficient data center power generation.
HOW BIOGAS SUPPORTS RELIABLE DATA CENTER OPERATION
In order to prove biogas as an effective and reliable power generation source, a real-world data center project was planned in Cheyenne, WY. Microsoft, University of Wyoming, FuelCell Energy, and Siemens partnered to identify and design a power generation system to utilize biogas to feed a fuel cell to power an on-site data center.
The Cheyenne data center project uses biogas — a byproduct that is naturally produced when stabilizing municipal waste — from the Dry Creek Water Reclamation Facility in Cheyenne to power the fuel cell-based data plant. Traditionally, the water reclamation facility would either vent this gas, which results in harmful environmental emission 20 times more hazardous than carbon dioxide, or flaring the gas that generates additional pollutants and wastes a potential fuel source.
Water treatment plants pair well with data centers because they’re both “always on.” Treatment plants because a community has water needs throughout a 24-hour day, and data centers because of constant online activity. These facilities will have the potential to change how the technology industry supports the cloud, providing more flexibility in locating data centers by making it possible to take a data center off the electric grid altogether.
Instead of wasting or emitting unnecessary hazardous gases into the atmosphere, the project captures biogas to power an onsite fuel cell. These cells, instead of traditional electrical power, will power the servers in the onsite data center. And any excess heat will be sent back to the sewage treatment facility to be used in anaerobic digestion to break down waste matter into energy. Anaerobic digestion is a series of biological processes in which microorganisms break down biodegradable material without using oxygen. One of the end products is methane, which can then be used to generate electricity and heat, or can be processed into renewable natural gas and transportation fuels.
Much like a battery, the fuel cells use an electrochemical process to convert chemical energy to electrical energy. In the case of the fuel cell, we are combining hydrogen and oxygen. During this process, ions move between special plates resulting in electron flow and producing the electricity to power the data center, energy output that is virtually absent of the pollutants that cause smog (NOx), acid rain (SOx), or can aggravate asthma (PM10).
Fuel cells hold promise because of their high electrical efficiencies and ability to be used in a very small space. At almost any size, fuel cells can operate extremely efficiently and with zero emissions running on hydrogen. It’s a fundamental difference between what is done today for power generation — using combustion — and what a fuel cell does, which generates power electrochemically.
The pilot effort integrates the water treatment, power plant, and data center, effectively eliminating energy loss that otherwise occurs in the energy supply chain and doubling the efficiency of traditional data centers.
FROM UNPROVEN TO PROVEN TECHNOLOGY
In order to prove the power generation system reliable enough to deliver consistent, high-quality power, monitoring equipment and software can be utilized to measure overall performance and energy output. A power monitoring system is similar to a car’s dashboard. When driving and pressing the gas pedal, the car will move but it’s unknown how quickly. It’s the speedometer that indicates speed and ensures safety efficiency. Check engines lights come on to warn you of problems, and RPMs show efficiency.
A power monitoring system works in the same way. Operators can see the energy being monitored and measured in real-time. The technology includes predictive demand alert capability so the data center operators are made immediately aware of any power quality or energy demand issues and allows operators to collect daily reports on the input and output of the system. With this insight, a data center can fully rely on biogas and fuel cells to provide enough quality power to run critical operations. And insight allows previously unproven technologies like biogas to be reliable, efficient, and clean sources of power for full-scale power projects.
MOVING FORWARD
Operating on renewable biogas, the Cheyenne data center when compared to the Wyoming grid will emit 3.5 tons less NOx, 3.5 tons less SOx, and 2,910 tons less CO2 per year. The emissions savings is equivalent to removing 610 cars from the road for one year. It also has up to 80% total efficiency with combined heat and power (CHP) configuration.
In proving biogas a reliable source of energy for critical installations like data centers is another step forward in utilizing renewable and alternative energy resources in power infrastructure. Integrating the power generation and the data center can move the industry toward hyper efficiency across the entire energy supply chain. Ultimately, applying renewables in the growing data center industry is a trend that offers efficiency and sustainability in the power generation marketplace.
